The heating systems employed in many industrial applications generate large quantities of hot combustion products, that for health and safety reasons, must be removed from areas occupied by the public. The removal of hot gases produced by combustion is accomplished generally by use of vertical stacks that discharge the gases into the upper atmosphere. Maintaining an attractive finish on the outer surface of such stacks is extremely difficult, mainly because ornamental coverings, such as paint, applied directly to the surface tends to deteriorate rapidly and to break up. Such surface deterioration is due to thermal expansion and contraction of the stack due to the intermittent passage of gases therethrough and to variations in the flow of air over its surface due to wind changes and to change in radiation from night to day and the light. Furthermore, the corrosive nature of the combustion gases causes chemical attack on surfaces adjacent the stack. Consequently, an industrial stack usually exhibits an unattractive appearance that undesirably dominates the overall appearance of the industrial complex of which they form a part. In addition, it is difficult to maintain such finishes and, particularly, to repair localized damage. These problems arise in the case of gas turbine stacks, and the gas stacks of steam generating units, as well as the walls of boilers. In the latter case, there is also the problem that the boiler wall is usually covered with insulation and lagging which has a tendency to split, peel, and warp to a resulting unattractive appearance. These and other difficulties experienced with the prior art have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide an appearance system providing a simple and long lasting means for beautifying the exterior surfaces of a stack used to confine the movement of industrially-produced combustion products.
Another object of this invention is the provision of an appearance system in which a plurality of decorative panels are applied to an industrial structure in such a way that movement of the structure due to thermal expansion and contraction does not destroy the attractiveness of the panels.
A further object of the present invention is the provision of a decorative panel system which is simple in construction, which is inexpensive to manufacture and apply, and which is capable of a long life of useful service with a minimum of maintenance.
It is another object of the instant invention to provide an appearance system in which a series of decorative panels are applied to a vertical surface in such a way that warping of the surface does not cause shifting of the panels in such a way as to give a change in appearance to the casual observer.
A still further object of the invention is the provision of an appearance system for applying decoration to a vertical surface in such a way that its appearance does not change appreciably despite major changes in the geometry of the surface.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.